Pollutant Concentrations

Air quality readings will be available hourly from 7am to 11pm. Air quality readings from 12am to 6am will be made available at 7am on the same day.

Readings on 13 Jan 2015

View reading for:

Region

24-hr Sulphur dioxide(µg/m3)

24-hr PM10(µg/m3)

1-hr Nitrogen dioxide(µg/m3)a

8-hr Ozone(µg/m3)

8-hr Carbon monoxide(mg/m3)

24-hr PM2.5(µg/m3)

North

9(5)

20(20)

16(-)

30(13)

0.4(4)

9(36)

South

9(5)

24(24)

1(-)

34(14)

0.4(4)

9(36)

East

6(4)

19(19)

6(-)

49(21)

0.4(4)

11(47)

West

2(1)

24(24)

11(-)

47(20)

0.4(4)

10(42)

Central

8(5)

21(21)

24(-)

52(22)

0.3(3)

8(32)

1-hr PM2.5 (µg/m3)b Readings on 13 Jan 2015

View reading for:

Time

1am

2am

3am

4am

5am

6am

7am

8am

9am

10am

11am

12pm

North

9

11

8

10

7

7

8

12

9

13

10

9

South

8

8

4

6

5

6

5

9

9

17

16

16

East

15

8

13

11

15

11

10

14

11

17

12

14

West

9

12

5

12

4

10

7

9

9

16

18

19

Central

4

6

6

5

4

7

9

10

10

8

15

10

Time

1pm

2pm

3pm

4pm

5pm

6pm

7pm

8pm

9pm

10pm

11pm

12am

North

12

7

10

8

12

11

5

5

6

9

5

-

South

18

15

15

10

12

13

4

4

2

2

1

-

East

12

10

11

9

10

11

10

8

8

8

7

-

West

8

17

16

11

9

12

6

8

8

6

8

-

Central

10

9

8

8

9

10

7

8

4

4

6

-

Note:a Sub-index for nitrogen dioxide is reported only when the 1-hr concentration equals or exceeds 1130 µg/m3.

b There is no sub-index for 1-hr PM2.5.

3-hr PSI Readings from 1am to 12am on
13 Jan 2015

Time

1am

2am

3am

4am

5am

6am

7am

8am

9am

10am

11am

12pm

3-hr PSI

34

34

35

35

32

33

32

37

39

48

52

53

Time

1pm

2pm

3pm

4pm

5pm

6pm

7pm

8pm

9pm

10pm

11pm

12am

3-hr PSI

52

51

49

46

44

43

39

34

26

25

24

-

Hourly updates of 3-hr PSI readings are provided from 7am to 11pm. The 3-hr PSI readings from 12am to 6am will be made available at 7am on the same day. The 3-hr PSI readings are calculated based on PM2.5 concentrations only.